I first ran across test tube plants on eBay, which is a great source for them. Many nurseries who only sell in bulk to businesses and small shops and universities interested in conservation are using them to clone plants from tissue culture. Another common use is to start difficult seeds.
The plants are grown in agar ( a clear gelatin like substance ) with a bit of sugar and sometimes plant hormones. The supplies are easily found online.
I tried a couple of difficult seeds with out much success. Getting the seeds sterile without killing them is a bit of an art form. I’ll try some easier seeds next time.
This is a great way to buy expensive plants.
It’s a bit tricky deflasking them. All of the agar must be removed from the very tiny, fragile plants or it will mold and rot the seedling. I use toothpicks and a dish of water with about 15% bleach added. Soaking the seedlings helps.
Plants started this way do not have the coating necessary to retain water. They must first be placed in terrariums, under lights and steady room temperature. Slowly acclimate them to sunlight, temperature differences, and life outside the terrarium.
I’d start with a cheap flask of plants, it may take a few tries to get the hang of transferring them to a regular garden environment.
I plan to try starting more seeds in flasks, I’ll post the process and results.